• Korean Journal of Animal Reproduction
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• v.19 no.1
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• pp.1-7
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• 1995

This study was accomplished to illuminate factors of contamination of microbes in the culture medium and effect of antibiotics on prevention of contamination in the medium when bovine follicular oocyte was matured, fertilized and developed in vitro. 1. When washed or unwashed semen diluted with TCM 199 was incubated for 24∼72hr, contamination was come out. 2. When diluted semen with TCM 199 which has penicillin, streptomycin, gentamycin, kanamycin or nystatin was incubated for 24∼72hr, contamination was not come out only in kanamycin. 3. When imported semen which was diluted in TCM 199 with penicillin, streptomycin, gentamycin, kanamycin or nystatin was incubated for 24∼72hr, contamination was not come out in all treatments. 4. When semen which was diluted in BO, CZB, Ham's F10 or TCM 199 was incubated for 24∼72hr, kanamycin showed no contamination in all treatments, but gentamycin showed contamination in CZB, Ham's F10 and TCM 199. 5. When the semen diluted in BO was moved at 24hr after incubation into BO and incubated for 72hr, contamination was not come out, but when it was moved into the TCM 199 and incubated for 72hr, contamination was come out at 48 to 72hr of incubation. 6. When the semen diluted in BO, BO＋BSA or BO＋FBS containing gentamycin, kanamycin or nystatin was incubated for 24∼72hr, the diluted semen in BO or BO＋BSA showed no contamination in all antibiotics but the diluted semen in BO＋FBS showed no contamination only in kanamycin. 7.The Pseudomonas cepacia, Serratia liquefaciens, Klebsiella pneumaniae was respectively isolated in the semen of A, B, and C bull and the microbes are highly affected by amikacin, tobramycin and kanamycin. 8. When bovine folicular oocyte was in vitro matured, fertilized and developed in the simple medium with kanamycin, 26.6% was developed to over 32cell stage embryo.

• Journal of Embryo Transfer
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• v.21 no.2
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• pp.129-135
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• 2006

This study was conducted to investigate the effect of in vitro maturation (IVM) duration of porcine follicular oocytes on maturation rate, polyspermic rate, and subsequent embryo development. The nuclear maturation rates of oocytes matured for 36, 38, 40, 42 and 44 hr were similar between 68.0, 78.0, 79.5, 73.8 and 81.8% respectively. There was no significant difference in the rates of polyspermy after in vitro feritilization (IVF). The cleavage rate in the group of 36 hr was significantly higher in than that of 40, 44 hr (p<0.05) but not to 38 and 42 hr. The development rate to blastocyst stage was significantly higher in the group of 38 hr (23.1%) than that in the group of 44 hr (15.6%) (p<0.05) but not to 36, 40 and 42 hr. These results suggest that the aged oocytes for 44 hr is not required for the production of bias to cysts derived from porcine IVF embryos.

• Korean Journal of Animal Reproduction
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• v.27 no.2
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• pp.125-133
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• 2003

The present study was carried out to examine the effect of $\beta$-Mercaptoethanol ($\beta$-ME) on in vitro maturation (IVM) of porcine follicular oocytes and oxygen concentration with $\beta$-ME on in vitro development (IVD) of porcine IVM/IVF embryos. The results were summarized as follows. 1. The rates of nuclear maturation, penetrated oocytes, polyspermic oocytes, pronucleus formation and mean numbers of the penetrated sperms were not significantly different using NCSU-23 maturation media for 0, 25, 50 and 100 $\mu$M $\beta$-ME (P>0.05). 2. The rates of blastocyst formation at day 7 after in vitro fertilization were higher in oocytes matured with 25 $\mu$M $\beta$-ME (25.4$\pm$0.9%) than in those matured with 0 (14.5$\pm$1.6%), 50 (17.3$\pm$1.7%) and 100 $\mu$M (12.4$\pm$1.3%) (P<0.05). However, no differences ware found in total cell numbers of blastocyst among the treatments. 3. The rates of blastocyst formation at day 7 after in vitro fertilization were higher in the NCSU-23 Culture medium With 25 $\mu$M $\beta$-ME (23.6$\pm$2.8%) than in those Cultured With 0 (15.4$\pm$4.4%), 12.5 (17.5$\pm$2.3%) and 50 $\mu$M $\beta$-ME (18.6$\pm$2.1%) Under the 5% and 20% $O_2$ Concentrations (P<0.05). However, no differences was found in total cell numbers of blastocyst among the treatments. These results suggested that the addition of 25 $\mu$M $\beta$-ME in the IVM/IVD media were effective on the porcine embryo production. However, the rates of blastocyst formation and total cell numbers of blastocyst at day 7 of porcine IVM/IVF embryos were not significantly different in the NCSU-23 culture medium under 5% and 20% 02 concentrations.

• Korean Journal of Animal Reproduction
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• v.23 no.3
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• pp.263-270
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• 1999

This study was conducted to investigate effects of L-ascorbic acid and selenium on maturation, fertilization, and development ablity of porcine follicular oocytes in vitro. When the follicular oocytes were cultured in the media containing 0, 62.5, 100 and 300 $\mu$M of L-ascorbic acid for 40~44h, the percentages of germinal vesicle breakdown were 86.8, 92.9, 91.7 and 92.6% respectively, and the nuclear maturation rates (M II) were 44.7, 57.1, 52.8 and 53.7%. The nuclear maturation rates of treated groups were significantly higher than those of non-treated group (p＜0.05). When the follicular oocytes were cultured at 0, 0.4, 0.8, and $1.5\mu$M of selenium for 40~44h, the nuclear maturation rates of treated groups were significantly higher than those of non-treated group (p＜0.05). The addition of L-ascorbic acid or selenium to the maturation medium, the incidence of male pronuclear formation was significantly increased (p＜0.05) and polyspermy rate was significantly decreased (p＜0.05). The addition of L-ascorbic acid or selenium to the maturation medium increased the clevage rate, morula and blastocyst rate (p＜0.05). These results suggested that the addition of L-ascorbic acid and selenium to maturation medium increase the nuclear maturation rates, male pronuclear formation and normal embryonic development: in porcine oocytes matured and fertilized in vitro.

• Journal of Embryo Transfer
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• v.16 no.2
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• pp.91-98
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• 2001

We evaluated the effects of the substrate and inhibitors related to phosphatidylinositol metabolism on in vitro maturation and fertilization of porcine oocytes. Cumulus-oocyte complexes were cultured in mTLP-PVA medium supplemented with or without inositol (250 mM) fur 46h. Subsequently, these oocytes were inseminated with fresh boar semen in mTALP-PVA medium for 6h. At 6h after insemination, oocytes were cultured for further 12 h in TCM-199 supplemented with 10% FBS (fetal bovine serum). The higher percentage of oocytes in inositol-supplemented medium reached metaphase of the second meiotic division compared to those in control (81.4% vs. 67.3%; P<0.()5). following 18 h of insemination, more number of male pronuclei were formed in the oocytes matured in inositol-supplemented medium than in those of control experiment (42.0% vs. 27.3%; P<0.05). When oocytes were cultured in medium with 10mM LiCl (chloride lithium) or 0.5mM dbcAMP (dibutyryl cyclic adenosine monophosphate) to determine the role of inositol on the maturation of oocytes, these two drugs inhibited the meiotic division of oocytes (P<0.05). However, addition of inositol to the culture medium did overcome the inhibitory effect of these drugs on the oocyte maturation. DbcAMP and verapamil supplemented synergistically arrested the meiotic division of oocytes. Addition of verapamil did not inhibit germinal vesicle breakdown, but it severly inhibited the second meiotic division of oocytes. These results suggest that inositol exert its improving effects on maturation, by activating the PI (phosphatidylinositol) cycle and causing beneficial changes in both cytoplasm and membrane of oocytes.

• Journal of Animal Reproduction and Biotechnology
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• v.34 no.3
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• pp.212-221
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• 2019

Sestrin-2 (SESN2) as a stress-metabolic protein is known for its anti-oxidative effects as a downstream factor of PERK pathways in mammalian cells. However, the expression patterns of SESN2 in conjunction with the UPR signaling against to ER stress on porcine oocyte maturation in vitro, have not been reported. Therefore, we confirmed the expression pattern of SESN2 protein, for which to examine the relationship between PERK signaling and SESN2 in porcine oocyte during IVM. We investigated the SESN2 expression patterns using Western blot analysis in denuded oocytes (DOs), cumulus cells (CCs), and cumulus-oocyte complexes (COCs) at 22 and 44 h of IVM. As expected, the SESN2 protein level significantly increased (p < 0.01) in porcine COCs during 44 h of IVM. We investigated the meiotic maturation after applying ER stress inhibitor in various concentration (50, 100 and 200 μM) of tauroursodeoxycholic acid (TUDCA). We confirmed significant increase (p < 0.05) of meiotic maturation rate in TUDCA 200 μM treated COCs for 44 h of IVM. Finally, we confirmed the protein level of SESN2 and meiotic maturation via regulating ER-stress by only tunicamycin (Tm), only TUDCA, and Tm + TUDCA treatment in porcine COCs. As a result, treatment of the TUDCA following Tm pre-treatment reduced SESN2 protein level in porcine COCs. In addition, SESN2 protein level significantly reduced in only TUDCA treated porcine COCs. Our results suggest that the SESN2 expression is related to the stress mediator response to ER stress through the PERK signaling pathways in porcine oocyte maturation.

• Development and Reproduction
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• v.10 no.4
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• pp.239-245
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• 2006

Experiments were conducted to determine the effects of beta-mercaptoethanol(${\beta}-ME$) supplements to the maturation medium on in vitro fertilization(IVF) and intracellular glutathione(GSH) concentration. Bovine cumulus-intact oocytes were matured in TCM-199 medium containing FBS, hormonal supplements, and ${\beta}-ME$(0, 25 and $50\;{\mu}M$) for 12h and 24 h. After culture, cumulus-free matured oocytes were co-incubated with frozen-thawed spermatozoa for 24h. Maturation rate increased(p<0.05) in ${\beta}-ME$ treatment group, but no significant differences among treatment groups. Also, increases(p<0.05) in intracellular GSH concentration before and after fertilization were observed in $50\;{\mu}M\;{\beta}-ME$ supplements to the maturation medium. Male pronuclear formations after IVF was increased(p<0.05) in ${\beta}-ME$ treatment group, but no significant difference among treatment groups. In conclusion, supplementing ${\beta}-ME$ into the maturation medium increased maturation rates, fertilization rates, and intracellular GSH concentrations.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.4
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• pp.398-403
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• 1998

The objective of the present study was to examine the developmental rates, and the stage of development in relation to time since fertilization, of in vitro produced buffalo embryos. Buffalo cumulus-oocyte complexes obtained from slaughterhouse ovaries were matured and fertilized in vitro. The fertilized oocytes (n = 248) were then co-cultured with buffalo oviductal epithelial cells and evaluated for the developmental stages on Days 2, 4, 6, 7, 8, 9 and 10 post-insemination. The peak of 4-cell stage embryos was observed on Day 2 (63.7 %), whereas Day 4 was marked by peaks of 6-8-cell stage embryos (20.9%) and 16-cell stage embryos to early morulae (50%). On Days 6, 7, 8, 9, and 10 post-insemination, 49.5, 48.3, 38.3, 33.8 and 33.4% embryos were found to be at morula/compact morula stages, 8.8, 12.5, 25.4, 6.0 and 1.2% at early blastocyst/blastocyst stages, 0, 6.8, 7.2, 15.3 and 2.0% at expanded blastocyst stage and 0, 1.6, 4.8, 19.3 and 38.5% hatching/hatched blastocyst stages, respectively. The peaks of early blastocyst/blastocyst, expanded blastocyst and hatching/hatched blastocyst stages were observed on Days 8, 9 and 10, respectively. The percentages of oocytes which initially became arrested and subsequently degenerated were 3.6, 4.8, 10.4, 14.5, 21.3 and 24.5% on Days 4, 6, 7, 8, 9 and 10 post-insemination, respectively.

• Korean Journal of Animal Reproduction
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• v.25 no.2
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• pp.181-189
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• 2001

The objective of this study was to evaluate the development of porcine follicular oocytes fertilized by intracytoplasmic sperm injection (ICSI). Cumulus-oocyte-complexes (COCs) were collected by aspiration from follicles of 2~7 mm in diameter from a local slaughterhouse. Oocytes were matured in vitro for 40~44 h, and spermatozoa were prepared by swim-up in the presence or absence of 5 mM dithiothreitol (DTT) and then M II stages of the oocyte were either centrifuged or not centrifuged for the following injection of ooplasm. Injected oocytes were cultured in NCSU 23 medium for 6 to 8 days. The results obtained were as follows: 1. The rates of cleavage and development rates into blastocyst by ICSI were not significantly different between the with (53.0% and 19.7%) or without (48.3% and 23.8%) centrifugation, respectively (P＜0.05). 2. The cleavage and developmental rates to blastocyst after ICSI with or without 5 mM DTT treated-sperm were not significantly different (60.4% vs 16.4% and 45.5% vs 22.2%), respectively (P＜0.05). 3. The cleavage and the developmental rates to btastocyst were not significantly different between the zygotes obtained by IVF (51.8% vs. 22.4%) and ICSI (51.4% vs. 21.6%) (P＜0.05). 4. The number of blastomere in blastocyst stages after IVF or ICSI was not significantly different (46.7$\pm$2.9 and 41.9$\pm$4.6).

• Reproductive and Developmental Biology
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• v.29 no.2
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• pp.127-131
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• 2005

The objective of this study was to examine the effect of EGF on meiotic maturation and pronuclear (PN) formation of porcine oocytes. Prepubertal gilt cumulus-oocyte-complexes (COCs) aspirated from $2\~6mm$ follicles of abbatoir ovaries were matured in TCM199 containing 0.1mg/ml cysteine, $0.5{\mu}/ml$ FSH and LH, and EGF (0, 5, 10, 20, 40 ng/ml) for 22 hr at $39^{\circ}C$ in a humidified atmosphere of $5\%$ $CO_2$ in air. They were then cultured for an additional 22hr without hormones. In Experiment 1, to examine the nuclear maturation at 44hr of culture, the expanded cumulus cells were removed by vortexing for 1 min in 3 mg/ml hyaluronidase. The oocytes were fixed in acetic acid: methanol (1:3, v/v) at least for 48 hr and stained with $1\%$ orcein solution for 5 min. Nuclear status was classified as germinal vesicle (GV), germinal vesicle breakdown (GVBD), prophase-metaphase I (PI-MI), and PII-MII under microscope. In Experiment 2, to investigate PN formation, oocytes were fertilized with Percoll-treated freshly ejaculated sperm $(1\times10^5\; cells/ml)$ in mTBM with $0.3\%$ BSA and 2mM caffeine for 5hr, and cultured in NCSU-23 medium with $0.4\%$ BSA. At 6hr of culture, the embryos were fixed in $3.7\%$ formaldehyde for 48hr and stained with 10ug/ml propidium iodide for 30 min. PN status was classified as no or one PN (unfertilized), 2 PN (normal fertilized) and $\geq3$ PN (polyspermy). Differences between groups were analyzed using one-way ANOVA after arc-sine transformation of the proportional data. The rate of oocytes that had reached to PII-MII were significantly (P<0.05) higher in all groups added EGF than that of non-treated group $(67\%)$, but it did not differ among the all added groups $(86\%,\;85\%,\;79\%\;and\;81\%$, in 5, 10, 20 and 40 ng/ml EGF, respectively). No differences on the incidence of 2PN were observed in all treated groups $(25\%,\;30\%,\;33\%,\;29\%\;and\;29\%$, in 0, 5, 10, 20 and 40 ng/ml EGF, respectively), however, in non-treated group, polyspermy tended to be increased ($66\%\;vs\;. 58\%,\;54\%,\;52\%\;and\;55\%$, 0 vs. 5, 10, 20, 40 ng/ml EGF, respectively). These results suggest that EGF can be effectively used as an additive for enhancing oocyte maturation and reducing the incidence of polyspermy in pig.